One man is dead after a fire at a senior-living apartment complex Wednesday night in Mesa, according to the Mesa Fire Department.

Officials said Keith J. Thomas,71, lived alone in the independent living section of the senior complex in a second-story apartment.

Police received a call at about 7:30 p.m. about a fire at the complex in the 200 block of East Brown Road.

Firefighters saw flames and heavy black smoke coming out of a second-story apartment when they arrived, according to the Fire Department.

Capt. Dean Morales, a Mesa Fire Department spokesman, said Thomas was found in the kitchen area with burns on his body and was pronounced dead at the scene.

Morales said the smoke alarm did go off, but investigators have not determined the cause of the fire or the cause of Thomas' death at this time. A forensics crime scene unit from the Mesa Police Department was on scene.

It is not known if Thomas had any medical conditions, Morales said.

The fire did not impact any of the neighboring apartments, according to Morales.

Morales said a security guard responded when the fire alarm went off but could not get into the complex. The security guard then called 911, according to Morales.